16. Data Quality

This chapter discusses the overall quality of the GFS statistics included in each release of data for a given period.

In any statistical undertaking, there is usually some trade-off between accuracy, reliability and timeliness. The trade-off involves balancing users’ requirements for timely statistics against the time and cost (of the ABS and data suppliers) required to collect and compile statistics of a given degree of accuracy and reliability. Generally, any improvement in timeliness comes at the expense of accuracy and reliability.

In this discussion, accuracy is defined as the closeness of an estimate to the ‘true’ value. Reliability is defined as the stability of an estimate as measured by the size and frequency of revisions made to the estimate over time. These two attributes should always be considered together, as it is possible to have a statistic that is reliable (because it is revised infrequently) but always inaccurate. In general, timeliness refers to the amount of time between the end of the period to which the statistics refer and the date of first release of the statistics to users.